FR3030110A1 - METHOD FOR COATING AN ELECTRONIC COMPONENT - Google Patents

Abstract

The present invention relates to a method for coating an electronic component comprising a substrate (41) on a front face (43) from which protrudes at least one interconnection member (42), the method comprising a coating made with a coating for coating at a surface of the front face (42) outside the at least one interconnection member (42), characterized in that the covering comprises the formation of at least one stack (6) of a plurality of layers on an area of said surface.

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a method of coating an electronic component, a method of assembling a first electronic component and a second electronic component, as well as an electronic component. The latter may include electrical or electronic organs, active as well as passive. The microelectronics industry, which is here considered to include nanotechnologies, is concerned.

STATE OF THE ART Electronic or computer systems are increasingly compact and, to this end, the use of integrated circuits has become widespread. In order to produce increasingly complex complex circuits, it is known to superimpose components, in particular to form three-dimensional assemblies whose height dimension limits the lateral bulk and often reduces the length of the connection paths. electric. For example, chips can be directly hybridized with solder balls on multilayer substrates providing the interconnections between the chips. A technique called "flip-chip" leads to the hybridization of hundreds of chips on substrates, by individual report chips on a substrate. In general, a transfer comprises facing two faces of two components (such as a chip and a main substrate), with an electrical connection of interconnection members present on each of the faces. An electrically coherent assembly is thus formed in a stack.

In order to reduce the thickness of the components, while increasing the density of the integrations, mechanical strength and / or air exposure problems of the interconnection members, such as solder balls, it is known to proceed to a coating of the active face of the components. In recent years, several coating techniques have developed. These techniques can be classified into two broad categories: the coating applied after assembly called "post-coating" and the coating applied before assembly called "pre-coating". By way of example, a process for coating electronic components before assembly, also called "spin coating", consists in depositing a calibrated drop of a coating substance such as a coating resin on the face of the coating. component to be covered. Rotation of the component induced by a rotating support produces a spread of the resin over the entire face of the component around the interconnecting members. Publication WO-A1-2008 / 069805 shows that this technique, like others, is difficult to adjust to obtain the desired coating. In particular, this document explains that effective coating is difficult to combine with non-overlapping interconnect devices; a solution is proposed, which requires an additional repellent product avoiding the pollution of the interconnection members by the coating resin. In general, there is a need to improve the coating of components, particularly in the pre-coating phases. Current techniques are indeed limited in the coating configurations that can be obtained. SUMMARY OF THE INVENTION An embodiment of the invention relates to a method for coating all or part of an electronic component comprising a substrate on a front face from which at least one interconnection member protrudes, the process comprising a coating made with a coating coating at a surface of the front face outside the at least one interconnection member. Advantageously, the covering comprises the formation of at least one stack of a plurality of layers on at least one zone of said surface. Preferably, the formation of at least one stack is carried out by an additive manufacturing method in wherein the layers of the plurality of layers are formed successively. Thus, the invention offers a new solution for operating the coatings, with stacks of layers, including, in particular, the nature, number and shape can be adapted as needed. For example, one can surround the interconnection members with the coating material, without risking pollution of these bodies. Other examples of advantages are given below. While current techniques are all "full plate" oriented in the sense that they necessarily imply a complete overlap of the component face, the present invention fights this prejudice and offers the possibility of localized coating coatings. In addition, by using multilayer additive manufacturing techniques, the invention may, according to some embodiments, very finely adjust the thickness of the stacks to be produced.

According to other aspects of embodiments of the invention, there is described a method of assembling a first electronic component comprising a first substrate on a front face which projects at least one first interconnection member and a second electronic component comprising a second substrate on a front face from which at least one second interconnection member protrudes, a method in which a step of contacting at least one pair of interconnection members is carried out, said pair comprising a first interconnection member and a second interconnection member, by approaching the front faces of the first and second components, characterized in that it comprises, before the contacting step, a coating of any or part of at least one of the first electronic component and the second electronic component by implementing the previously introduced method. By sequencing a suitable coating according to the invention, and then an assembly of two components, it is possible, for example, to produce a flow of the coating coating during assembly so as to fill the interspaces between the interconnecting members. Also disclosed is an electronic component having a substrate on a front face from which protrudes at least one interconnecting member, having a coating coating at a surface of the front face apart from at least one body member. interconnection, characterized in that the coating comprises at least one stack of a plurality of layers on an area of said surface. Other aspects of the invention are a component obtained by the coating process and a set of components obtained by the assembly process. The invention also relates to a system of components according to the invention assembled by their front faces. BRIEF DESCRIPTION OF THE DRAWINGS The objects, objects, as well as the features and advantages of the invention will become more apparent from the detailed description of an embodiment thereof which is illustrated by the following accompanying drawings in which: FIGS. the at present the potential successive steps of manufacturing a system of components assembled with, in Figure la, the positioning for example of a plate still often called in English "wafer", on a support, in Figure 1 b the bucking of the plate into a plurality of individual components, in Figure 1 the manipulation of one of these components to be reported in Figure 1d on a predetermined area of another component to assemble as in Figure 1 e; FIGS. 2 to 4 show embodiments of a first layer of a stack for forming a coating coating on the surface of a component; Figures 5 to 9 show different embodiments of stack configurations on the surface of the component; - Figures 10 and 11 show two embodiments of a component assembly; - Figures 12 to 14 show variants of the invention with interconnect members of various shapes; Figures 15 to 17 show embodiments for an assembly of two components; FIGS. 18 to 20 show a first possibility of layer fabrication, by the additive method known as "Fused Deposition Modeling" (or deposition of molten filament); FIGS. 21 and 22 show a second example of an additive manufacturing method called "stereolithography". The accompanying drawings are given by way of examples and are not limiting of the invention. These drawings are schematic representations and are not necessarily at the scale of the practical application. In particular, the relative thicknesses of the layers and substrates are not necessarily representative of reality. DETAILED DESCRIPTION Before going into the detail of embodiment of the invention, particularly with reference to the drawings, nonlimiting features which the invention may present individually or in any combination are briefly introduced hereinafter: is operated so that the at least one stack does not cover the entire surface of the front face outside the at least one interconnection member; the formation of at least one stack comprises a formation of a stack with at least two layers of the plurality of layers made of different materials; the materials of the at least two layers have different physical characteristics chosen from: electrical conductivity, thermal conductivity, viscosity, elasticity, hardness, coefficient of thermal expansion; the layers of different materials are deposited several times alternately; The formation of at least one stack comprises the formation of a plurality of stacks on distinct areas of the surface of the front face; optionally, a given stack may be associated with one or more interconnection members; the plurality of stacks comprises at least two stacks of different heights; at least one stack comprises at least two layers of different sections in a plane parallel to a plane defined by the front face of the substrate; the height of the at least one stack is greater than or equal to that of the at least one interconnection member; nevertheless the opposite situation is possible; the formation of at least one primary stack on the front face of the first substrate and at least one complementary stack on the front face of the second substrate, said primary and complementary stacks being configured to form a pair of stacks of so that, when the front faces of the first and second components are brought together, said primary and complementary stacks are brought into contact; the resulting height of the pair of stacks is chosen to be greater than that of any one of the at least one pair of interconnection members; in the opposite case, at least one of the interconnection members of the corresponding pair is preferably chosen from a material capable of deforming or designed to allow contacting during assembly (insertion, interlocking, etc.). said primary and complementary stacks; when approaching the front faces of the first and second components, the exercise of a relative pressure between the first and second components is configured to deform plastically at least partially of the primary stack and / or the complementary stack; this lamination can be assisted by heating (thermocompression). Thus, to obtain said plasticization, the following parameters can be used: pressure, time and temperature; this plasticization can take place at one or more layers of at least one stack; the plasticization may comprise a flow of at least one coating layer of a non-crosslinked or non-cross-linked polymeric material; optionally after the exercise of a pressure, a final step of crosslinking said at least one coating layer is performed. the formation of at least one individual stack is carried out on the front face of the first substrate without making any overlap on a portion of the surface of the front face of the second component, said portion being located opposite said individual stack during the approximation front faces of the first and second components, the height of said individual stack being chosen so that, on approaching the front faces of the first and second components, said individual stack and said portion 10 are brought into contact; the height of said individual stack is chosen greater than the resultant height of any one of the at least one pair of interconnection members; of course, as before, in the opposite case, at least one of the interconnecting members of the corresponding pair 15 is preferably chosen from a material capable of deforming or designed to allow the individual stack to be brought into contact with said portion during assembly. - When bringing the front faces of the first and second components, the exercise of a relative pressure between the first and second components 20 is configured to plastically deform at least partially the individual stack. the plastic deformation comprises a flow of at least one layer of the coating stack, said layer being made of a non-crosslinked or non-fully crosslinked polymer material. After the exercise of a pressure, a final crosslinking step of the said at least one coating layer is carried out; an assembly is made from a first and a second component configured to form two pairs of adjacent interconnection members, in which at least one stack is formed interposed between the two pairs of interconnection members. adjacent, and in which, when the front faces of the first and second components are brought together, at least one interposed stack is at least partially plastically deformed so that it completely fills a space between the two pairs of members, one of the front face of the first substrate and the front face of the second substrate and a predetermined height level from said one of the front face of the first substrate and the front face of the second substrate; the predetermined height level of the stack is chosen equal to the resulting height of the pairs of adjacent interconnecting members after assembly. It is specified that in the context of the present invention, the term "over", "overcomes" or "underlying" or their equivalent do not necessarily mean "in contact with". For example, the deposition of a second coating layer on a first layer does not necessarily mean that the two layers are in direct contact with each other but that means that the first layer at least partially covers the second layer being either directly in contact with it or separated from it by another layer or another element. In the following description, the thicknesses are generally measured in directions perpendicular to the plane of the front face, the thickness dimension corresponding to that of the substrate of the component. A definition of certain terms used in the present description is given below. Optionally, examples of structural implementations of elements corresponding to these terms are given for non-limiting purposes. The term "electronic component" refers to any device that may have application in the field of electronics and microelectronics, the term "microelectronics" being considered as integrating nanotechnologies. The term "electronic component" is not limited to components having an electrical function. In this sense, the term "interconnection member" designates any member for making a connection between two parts of an assembly, in particular two components assembled by a transfer. The interconnection can therefore be electrical, so as to electrically connect the two components, but also or alternatively for example mechanical, to participate in the mechanical connection between the components. Interconnecting members may be balls, tubular interconnections of the insert type, or, for example, preforms. A preferred technique for the multilayer embodiment of the coating is additive manufacturing. The term covers the techniques of manufacturing by adding material and in several layers. This is a method of forming a part by adding material and stacking successive layers. A definition of additive manufacturing is given by ASTM International (standardization body).

By way of illustration, for an additive manufacturing method, the base material may be mainly used in liquid, powder, wire or ribbon form. This material may be present from the beginning of the manufacturing process or deposited as this process progresses. A stereolithography process consists in insolating a layer for a layer of photosensitive material present in liquid form in a basin. As the mobile platform descends into the resin bin, for example an ultraviolet laser scans the areas to be crosslinked defined by the digital model. In the case of a contribution of material during manufacture, it is possible to implement a method of manufacture by molten plastic filament (Fused deposition Modeling (FDM) in English). With this process, the base material is supplied as the workpiece is made using a heating nozzle which moves to the locations defined by the numerical model. The shaping of the material can be done with a laser, a visible light, ultraviolet or infra-red, or thanks to a source of heat. The shaping process can be physical (melting, sintering, etc.) or chemical (polymerization, crosslinking, etc.). Additive manufacturing also covers the Selective Laser Melting (SLM) process, which consists of melting, by laser scanning, metal powders deposited layer by layer. The Selective Laser Sintering (SLS) process operates on the same principle with the only difference that the powders are not melted but sufficiently heated to reach the powder weld. Other additive manufacturing technologies are electron beam fusion, polyjet, direct material deposition or inkjet printing. The so-called 3D 3D printing techniques are considered to be included in the term "additive manufacturing". The term "substrate" refers to any semiconductor medium or not, forming all or part of a component. It can be mono or multilayer. Typically, the orientation of the substrate defines, on both sides of its thickness, two faces. One of the faces, at which one wishes to achieve a coating, is here called front face in that it comprises one or more interconnection members for the docking of another component. It is not excluded that the other face is coated. It is also possible that this face has interconnection members. - The coating coating can serve as an electrical insulator. It can also have an electrical conduction function insofar as, advantageously, the invention offers the possibility of adjusting the conductance of the stack by selecting the material or materials of the stack according to their conductivity.

3030110 9 Figures la to show some possible manufacturing steps for a system of assembled components. In Figure la, there is illustrated a support 1 receiving a plate 2 on which have been previously formed a plurality of electronic components. By way of example, such a plate, also called "wafer", may be in the form of a substrate, for example a semiconductor material with a plurality of components and electronic circuits formed on at least one face of the components. Any other component configuration is within the scope of the present invention.

The plate 2 incorporating the various components is the object in FIG. 1b of a cutout in a plurality of individual pieces each producing a component 3. The cutouts are produced along cutting lines, an example of which is given at reference 21 in FIG. 1 b. In Figure 1c, schematized the gripping of a component 3 among the 15 cut components, this component being intended to be assembled with another component 4 schematized by the surface 4 in Figure ld. The assembly zone between the two components 3, 4 is also shown schematically in this figure. To achieve the assembly, it is possible, for example, to use interconnection devices which will advantageously make it possible both to produce electrical continuity between the two components 3, 4 and to make all or part of the mechanical assembly between the components. For example, it is possible to use solder microbeads whose material goes between the two components 3, 4 to produce an autogenous weld. A result is shown schematically in Figure 1 e. The invention does not make any assumption about the type of component 4 to which the component 3 can be related. Nevertheless, it may for example be a component 4 of larger surface dimension, the component 4 being able to receive one or more components 3 and be itself a multi-component cutting substrate. The illustrations given in FIGS. 2 to 9 are made in the example of a coating of a component 4, but it is understood that the same type of coating can be applied to component 3. Furthermore, the embodiment of a coating on a front face of at least one component before assembly shown in Figures ld and is known per se. In general, it will seek to cover only the portion of the front face located outside the interconnection members without covering them.

However, this possibility is not excluded by the invention. For example, it is not possible for a thin portion of the coating to be superimposed on all or part of at least one of the interconnecting members. FIG. 2 shows an example of such interconnect members in the form of balls made on a front face 43 of a substrate 41 of a component 4. In the case represented, the rear face 44 opposite to the front face 43 does not has no active or passive component. It is not excluded as far as this rear face 44 is itself the place of formation of one or more components. FIG. 2 also shows the production of a coating layer 5 on the front face 43. The coating materials which can be used are the polymeric materials.

For example, the following may be chosen as coating material: epoxy resins; photosensitive resins; thermoplastic polymers; thermosetting polymers; Waxes, varnishes or silicones. In the case of the example of Figure 2, the entire front face 43 outside the interconnection members 42 is covered by the coating layer 5. Figure 3 shows a variant with the coating layer 5 located only in a zone between the interconnection members 42, leaving a portion of the front face 43 not covered by the coating layer 5, here at the periphery of the component 4. It will be noted that the thickness of the layer of The coating 5 is advantageously much smaller than the height 45 of the interconnection members 42. Another variant is given in FIG. 4 with a coating layer 5 made in several discontinuous portions on the front face 43. between two interconnecting members 42 is completely covered while portions between other interconnection members 42 are only partially covered. The covered areas 7 can therefore be of particularly diverse configurations depending on the need for recovery of the front face 43.

The production of stacks 6 for producing the coating coating from stacked coating layers 5 makes it possible to obtain different coating configurations on the surface of the component 4. FIG. 5 illustrates one of them with a stack 6 made with seven successive coating layers 5, these different layers completely filling, up to a predetermined height level above the surface of the front face 43, 3030110 11 interspaces between the organs of interconnection 42. These remain however salient in the case of Figure 5. In the case of Figure 6, stacks 6 similar to those of Figure 5 are provided in three interspace between the interconnecting members 42.

However, at the periphery of this group of interconnection members 42, for example at the edge of the component 4, the stacks 6 are of lower height and are for example made by limiting the number of successive stacks. Thus, for example, some stacks have seven coating layers while the two peripheral stacks have only four coating layers 5. Optionally, more than one hundred layers may be formed. A stack comprises at least two layers. Another variant is made in FIG. 7 with stacks 6 not covering the entirety of the intermediate space between the interconnection members 42. Thus, the layers 6 are deposited successively in a local manner while leaving them remaining, starting from the front face 43, uncovered areas such as the portion 8 in Figure 7. In the case shown in Figure 7, the areas which are on the contrary covered with the reference 7, are of the same height and made with the same number of layers but this configuration is not limiting. Moreover, in FIG. 7, the height of the stacks 6 is less than the height 45 of the interconnection members 42 or, more generally, of the highest of the interconnection members 42 if the latter have different heights . In contrast, in the variant of Figure 8, at least one of the stacks 6 and for example all, have a height 61 greater than that of the interconnection members 42. It is understood that, in this case, the interconnection members 42 are accommodated in spaces such that the distal surface 63 of the stacks 6 is situated above the interconnection members 42 and possibly above any other member projecting beyond the front face 43. Both in FIG. 7 that in Figure 8, the stacks 6 are of the same nature and made with the same dimensions and the same shapes. This case is not limiting of the invention as shown in FIG. 9 with a plurality of stacks 6 having at least one different characteristic among: the height, the width, the lateral profile 62, the number of layers, etc. . An advantage of the adjustment of the stacks 6 is to be able to vary the total thickness deposited to adapt to the dimensions of the interconnections. Another cumulative or alternative interest is to allow optimum flow of the coating layers 5 during assembly which will be described in detail later. Another interest is to adjust the profile of the stack by changing the sections of the successive layers. With the invention it is possible to avoid the appearance of air bubbles, that is to say areas not filled by the coating material. The variation of the profile of the coating material 5 can also make it possible to avoid an excessive presence of coating material in certain places and to follow, for example, the profile of the interconnection members 42 to adjust more finely. to their shape. FIG. 10 illustrates an example of two components 3, 4 after assembly, in which example the coating coating has completely filled the interstitial spaces between the interconnecting members 42. In addition, a fillet net 10 has been formed on the periphery of the component 3 assembled on the component 4. The variation of the shapes or profiles of the stacks 6 allows in particular to adjust the shape of the fillet 10. Preferably, the volume of the coating material deposited in a plurality of layer 5 is adjusted so as to fill the final space between the components, filling the difference in height 9 illustrated in FIG. 11. This interspace reflected by the height 9 is generally controlled by the dimension of the interconnection members 42. at the deposition of a plurality of layers 5, the total thickness of the coating material can be finely controlled so as to adjust the volume of the coating material in operation In addition to the total filling of intercalated spaces between the interconnection members 42, an advantage of the present invention is the preservation, on the surface of the front face 43, of uncoated areas, for example at the cutting lines 21 schematically shown in Figure 1 b. At this level, the absence of coating avoids interfering with the cuts. In this regard, it will be noted that the coating of the component 4 or the component 3 can be performed before or after the cutting phase. Thus, preferentially, the coating phases will be carried out on complete platelets 2 and not on the already individualized components.

FIG. 12 also shows interconnection members 42 of different heights and the adaptation of the heights of the stacks 6 to the height of each interconnection member 42. FIGS. 13 and 14 show variants of the invention and FIG. applicability of the invention to interconnection members 42 of any kind. Thus, in the case of FIG. 13, the interconnections are of the hollow tube type and have a central hole 3030110 13 which must not be encapsulated. By cons, the peripheral spaces to the tubes are fully filled in the case of Figure 13. Alternatively, the interconnection members 42 may be of complex shapes as in the case of Figure 14 and the multilayer deposition allows to adapt to the profile of these complex organs. As indicated above, the successive coating layers can be made of one and the same material or different materials. For example, two or more different materials can be alternated. As many layers can be made as different materials to be deposited. For example, in areas where the filling of the interspaces between the interconnecting members 42 is easy to achieve by the deposition of the coating layers, use less viscous materials than in the areas where a filling of the interstitial spaces between the interconnection members 42 should be made by a flow during assembly. In these locations, on the surface layer or layers of the stack 6, more fluid materials may be used than for the underlying layers. The difference in materials can also be selected according to certain physical properties of the materials and in particular the electrical conductivity or the gas or liquid tightness. Examples of assembly between two components 3, 4 are described below.

As schematized in FIGS. 1d and 1e, the assembly 3, 4 is made by placing a front face 43 of the component 4 with respect to the front face of the component 3. The component 4 comprises interconnection members 42 just as component 3. In the case of Figure 15, the interconnection members 42 of the component 4 are solder balls and the interconnection members 31 of the component 3 are conductive patterns (pads and / or tracks) on the front face of this component 3. The interconnection members 42, 31 are arranged so as to be positionable facing to form a pair of interconnecting members 12 that can be brought into contact during the assembly phase, this phase being made in the direction of the arrow of Figure 15.

This figure further shows that component 4 has been coated by a plurality of layers forming complex configuration stacks. For example, it is noted that the distal ends of the stacks 6 of the component 4 are configured to contact areas of the front face of the component 3 located outside the interconnection members 31. In addition, the stacks 6 are 35 a height greater than the height of the interconnection members 42, so that the docking between the two components 3, 4 is effected first by the distal surfaces of the stacks 6. In the embodiment of this embodiment In addition, it will be noted that component 3 does not comprise a coating coating.

It is understood that, during assembly, a pressure exerted in the direction of the arrow will allow contacting of the stacks 6 with the surface of the component 3 and a progressive plastic deformation of the material of one or more layers of In this way, advantageously, all of the interspaces between the interconnecting members 42 and 31 and the front faces of the components 3, 4 will be filled, so that no gaps will be created. especially filled with air can not survive in these places. Plastic deformation is understood to include covering an at least partly irreversible (or permanent or residual) deformation, as opposed to elastic deformation in which a return to the initial shape is produced upon relaxation of the applied stresses. Preferably, to achieve a material flow of the coating layers 5 during the pressurization of the component 3 on the component 4, it is possible to use, for the layer or layers intended for this flow, coating materials having a dynamic viscosity of between 10-3 Pa.s (Pascal seconds) and 106 Pa.s, these values being taken preferably at 20 ° C. Another embodiment of an assembly of components 3, 4 is given in FIG. 16, at which time component 3 is equipped with stacks 6 of coating coatings. On the other hand, the component 4 is left bare at its front face 43. A similar operation to that previously described with reference to FIG. 15 can be implemented to achieve the docking between the two components having noted that the height of the stacks 6 is in this case at least equal to that of the interconnection members. It is also possible to have interconnect members higher than the coating thickness, and which deform or become stuck during assembly.

FIG. 17 shows another possibility in which coating coatings are as well formed on the component 3 as the component 4. For this purpose, pairs of stacks 6 bearing the reference 11 are thus produced so that a 6 of the component 4 cooperates with a stack 6 of the component 3. Preferably, it is arranged that the cumulative height of the stacks 6 of a pair of stacks 11 is greater than the cumulative height of the interconnection members 42 , 31 of a pair of interconnecting members 12.

The manufacture of the plurality of coating layers can be carried out by the various additive manufacturing techniques described above. Figures 18 to 20 show examples of such additive manufacturing by a FDM (Fused Deposition Modeling) deposition technique using a molten wire for deposition. With this basic process, the base material is provided as the coating layer 5 is produced by means of a heating nozzle forming a deposition head 13 which moves to predefined locations by a numerical control. In FIG. 18, the deposition of a first layer is thus particularly precise and makes it possible to completely fill the interstitial spaces between the interconnection members 42. The altitude along the z direction is adjusted as a function of the coating layer 5 to achieve and the typology of the surface, here defined by the xy plane. It is thus possible to deposit the coating material at the desired locations. The following layers can be made in the same way by modifying the altitude along the z direction as in the case of FIG. 19. The succession of these layers can be carried out by varying one or more layer parameters, for example the thickness, the surface of the deposit or the material. Another variant is given in FIG. 20, with a displacement of the head 13 such that the interconnection members 42 are avoided and the stacks 6 of coating layers are deposited locally. As before, these deposits are successive, iteratively carried out one coating layer 5 after the other. An alternative embodiment of the stack process 6 by depositing successively by depositing the coating layers 5 is given in FIGS. 21 and 22. This additive manufacturing process is of the stereolithographic type. In this case, the component 4 is placed on a support itself immersed in a bath of a coating solution 16. The support may in particular comprise a plate 15 having a mobility in a direction perpendicular to the xy plane (z direction Figures 18 to 20). In FIG. 21, the immersion of the component 4 in the coating solution 16 is carried out so as to leave a thin layer of the material of the coating solution 16 covering the front face 43. Then, an insolation head 14 is used to cross-link the desired areas of the coating solution 16 to form the coating layer 5. In the case of FIG. 21, only the interspaces between the interconnecting members 42 are cross-linked to form the coating layer. coating 5 at this location.

On the other hand, the zones situated at the periphery of the interconnection group at the borders of the component 4 are left free.

Subsequently, a progressive descent of the plate 15 inside the coating solution 16 makes it possible to reveal, above the coating layer 5, a new film of coating solution 16 which may in turn be This head can in particular be configured to generate a beam of ultraviolet light. The crosslinking positions may be different from one layer to another as in the previous cases. Once the succession of layers 5 has been carried out, the substrate is removed from the bath of the coating solution 16. Only the areas of insolated coating material remain on the component 4. The non-insulated coating material is removed and optionally a rinsing can be achieved.

It should be noted that the two examples of prior manufacturing techniques are not limiting. Also, it is possible to combine one or the other of these techniques with one or more other additive manufacturing techniques such as polyjet, jetting, laser sintering, etc. Thus, we can alternate the deposition technique. For example, a coating layer 5 may be made with a technology other than the technology used for the previous layer or the next layer. In particular, a first layer can be produced by stereolithography of a first material followed by stereolithography of a second material. In this case, it will be necessary to change the bath of the coating solution 16. The stereolithography of a coating layer 5 can also be carried out in a first material followed by FDM deposition (or any other additive manufacturing technology). ) for the same material or another material. An interest is to vary the type of coating material from one layer to another and in particular to be able to play on the insulating or electrically conductive properties as indicated above. It should be noted that it is advantageous to produce coating layers without crosslinking them or without completely crosslinking them after their deposition. In this way, a certain residual viscosity is left to the materials of the stacks 6 for the assembly phase between the components 3 and 4. Possibly, after the assembly, a final crosslinking can intervene so as to harden, advantageously totally this time. In general, one can use different techniques of crosslinking or polymerization, partial or total, both before and after the assembly of the two components. In particular, it is possible to: - carry out storage in temperature, in an oven in particular, for a predefined time. The temperature is preferably between 25 ° C and 450 ° C and 3030110 17 / or the storage time is greater than 1 second. For example, the Intervia® dielectric material from Rohm and Haas can be baked at 200 ° C for 2 hours; or the E512 resin from Epotecny can be stored at 25 ° C for 48 hours; Epoxy Technology Epo-tek® H2OE resin can be stored at 120 ° C for 15 minutes; - operate an insolation under ultraviolet rays; for example, the materials used are sensitive to wavelengths between 10 nm and 1 mm for insolation times greater than 1 second; according to one example, an "Epo-tek® 0G116-31" resin from Epoxy Technology, can be insolated by a UV lamp of intensity 100mVV / cm 2, at a wavelength of between 240 nm and 365 nm, and during 2 minutes ; according to another example, the Vitralit® 7989 resin can be insolated by a UV lamp of intensity 45 mW / cm 2, at a wavelength of 365 nm, and for 5 seconds; use materials capable of softening above a given temperature threshold, for example 20 ° C .; these materials may be thermoplastic polymers which can be indefinitely softened (reduced viscosity) or cured (increased viscosity) respectively by heating or cooling them.

3030110 18 REFERENCES 1. Bracket 2. Bracket 5 21. Cutting line 3. Component 31. Interconnect 4. Component 41. Substrate 10 42. Interconnecting member 43. Front 44. Back 45. Height 5. Coating layer 15 6. Stacking 61. Height 62. Profile 63. Distal surface 7. Covered area 20 8. Uncovered part 9. Spacing 10. Leave 11. Pair of stacks 12. Pair of interconnecting members 25 13. Depositing head 14. Insolation head 15. Tray 16. Coating solution

Claims (22)

REVENDICATIONS1. Process for coating all or part of an electronic component comprising a substrate (41) on a front face (43) from which at least one interconnection member (42) projects, the method comprising a covering made with a coating of coating at a surface of the front face (43) outside the at least one interconnection member (42), characterized in that the covering comprises the formation of at least one stack (6) of a plurality of layers on at least one area of said surface. The method of claim 1 wherein the formation of at least one stack (6) is performed by an additive manufacturing method wherein the layers of the plurality of layers are successively formed. 3. Method according to one of the preceding claims, wherein the covering is operated so that the at least one stack (6) does not cover the entire surface of the front face (43) outside the at least one organ interconnection (42). 4. Method according to one of the preceding claims wherein the formation of at least one stack (6) comprises a formation of a stack (6) with at least two layers of the plurality of layers of different materials. 5. Method according to the preceding claim, wherein the materials of the at least two layers have different physical characteristics selected from electrical conductivity, thermal conductivity, viscosity, elasticity, hardness, coefficient of thermal expansion. 6. Method according to one of the two preceding claims wherein the layers of different materials are deposited several times alternately. 7. Method according to one of the preceding claims wherein the formation of at least one stack (6) comprises forming a plurality of stacks (6) on distinct areas of the surface of the front face (43). . 8. Method according to the preceding claim, wherein the plurality of stacks (6) comprises at least two stacks (6) of different heights. 9. Method according to one of the preceding claims, wherein at least one stack (6) comprises at least two layers of different sections in a plane parallel to a plane defined by the front face (43) of the substrate (41). 3030110 20 10. Method according to one of the preceding claims wherein the height of the at least one stack (6) is greater than or equal to that of the at least one interconnection member (42). 11. A method of assembling a first electronic component (4) comprising a first substrate (41) on a front face (43) of which projects at least a first interconnection member (42) and a second component. electronic device (31) comprising a second substrate on a front face (43) from which protrudes at least a second interconnection member (3), in which process a step of contacting at least one pair of members is carried out interconnection (12), said pair comprising a first interconnection member (42) and a second interconnection member (31), by approaching the front faces of the first and second components (3, 4), characterized in that it comprises, before the step of bringing into contact, a coating of all or part of at least one of the first electronic component (4) and the second electronic component (3) by implementing the method according to the invention; one of the preceding claims. 12. Method according to the preceding claim wherein is carried out the formation of at least one primary stack on the front face (43) of the first substrate (41) and at least one complementary stack on the front face of the second substrate, said primary and complementary stacks being configured to form a pair of stacks (11) so that, when the front faces (43) of the first and second components (3, 4) are brought together, said primary and complementary stacks are brought into contact with each other. . 13. The method according to the preceding claim, wherein the resulting height of the pair of stacks is chosen to be greater than that of any one of the at least one pair of interconnecting members. 14. Method according to the preceding claim, comprising, on approaching the front faces of the first and second components (3, 4), the exercise of a relative pressure between the first and second components configured (3, 4) to operate. at least partial plasticization of the primary stack and / or the complementary stack. 15. Method according to one of claims 11 to 14, wherein the formation of at least one individual stack on the front face (43) of the first substrate (41) without performing recovery on a portion of the surface of the front face of the second component (4), said portion being located opposite said individual stack when the front faces of the first and second components (3, 4) are brought together, the height of said individual stack being chosen so that, 3030110 21 when approximation of the front faces of the first and second components (3, 4), said individual stack and said portion are brought into contact. 16. The method according to the preceding claim wherein the height of said individual stack is chosen to be greater than the resultant height of any one of the at least one pair of interconnecting members (12). 17. Method according to the preceding claim, comprising, on approaching the front faces of the first and second components (3, 4), the exercise of a relative pressure between the first and second components configured to perform at least partial plasticization of individual stacking. 10 18. Method according to the preceding claim or claim 14, wherein the plasticization comprises a flow of at least one layer of the coating stack, said layer being made of a non-crosslinked or non-fully crosslinked polymer material. 19. Method according to the preceding claim, comprising, after the exercise of a pressure, a final step of crosslinking said at least one coating layer. 20. Method according to one of claims 11 to 19 for assembling a first and a second component (3, 4) configured to form two pairs of interconnecting members (12) adjacent, wherein forms at least one stack interposed between the two pairs of adjacent interconnection members, and wherein, on approaching the front faces of the first and second components (3, 4), at least one of said at least one stack is at least partially plasticized; interposed so that it completely fills a space between the two pairs of members, one of the front face of the first substrate and the front face of the second substrate and a predetermined height level from said one from the front face (43) of the first substrate and the front face of the second substrate. 21. Method according to the preceding claim wherein the predetermined height level is chosen equal to the resulting height of the pairs of interconnecting members (12) adjacent after assembly. An electronic component comprising a substrate on a front face from which at least one interconnection member protrudes, comprising a coating coating at a surface of the front face outside the at least one interconnection member, characterized in that the coating comprises at least one stack of a plurality of layers on an area of said surface. 35